Tornadoes · United States · Colorado · 2004

F0 tornado, Arlington, Colorado, August 7, 2004

This F0 tornado ran 1.0 miles across Kiowa County on August 7, 2004, touching down at 5:00 PM MDT and reaching 75 yards wide. It killed nobody, and did $10,000 of property damage.

The rating scale

Tracks are drawn in the color of the rating. The Fujita scale rates the damage rather than measuring the wind: the speeds are what that damage is taken to imply.

  1. F040 to 72 mphthis tornado

    Light damage. Surface peeled off some roofs, gutters and siding damaged, branches broken, shallow-rooted trees pushed over.

  2. F173 to 112 mph

    Moderate damage. Roofs badly stripped, mobile homes overturned or badly damaged, exterior doors lost, windows broken.

  3. F2113 to 157 mph

    Considerable damage. Roofs torn off well-built houses, frame homes shifted on their foundations, mobile homes destroyed, large trees snapped or uprooted, cars lifted off the ground.

  4. F3158 to 206 mph

    Severe damage. Whole stories of well-built houses destroyed, large buildings badly damaged, trains overturned, trees debarked, heavy cars lifted and thrown.

  5. F4207 to 260 mph

    Devastating damage. Well-built houses leveled, structures with weak foundations moved some distance, cars thrown and large missiles generated.

  6. F5261 to 318 mph

    Incredible damage. Strong frame houses swept off their foundations, car-sized missiles thrown more than 100 meters, steel-reinforced concrete badly damaged, high-rise buildings deformed.

  7. Unrated

    The survey recorded a tornado but could not put a number on it, most often because it crossed open country and damaged nothing a rating can be read from.

The record

Rating
F0
Date
August 7, 2004
Touchdown
5:00 PM MDT (23:00 UTC)
Path length
1.0 miles (1.6 km)
Path width
75 yards (69 m)
Deaths
0
Injuries
0
Property damage
$10,000
County
Kiowa County
Touchdown point
38.300, -103.230
Lift-off point
38.300, -103.220
Record number
1544

What the Weather Service recorded

Two short-lived tornados moved very slowly over open country and caused no known damage.

Around Blue Lakes Reservoir...three tornadoes were observed in close proximity. One of these tornados hit a camper and destroying it.

From NOAA NCEI's Storm Events Database, the narrative the local forecast office wrote for Storm Data.

The warnings

1 minute of warning. NWS PUB issued a tornado warning for this county at 22:59 UTC, 1 minute before the tornado touched down, in force until 23:45 UTC.

Issued (UTC)ExpiredProductOffice
22:59 UTC23:45 UTCTornado WarningPUB
00:10 UTC01:15 UTCTornado WarningPUB

Every warning and watch covering the touchdown point that day, from the Iowa Environmental Mesonet's archive of National Weather Service products. Lead time is measured from the issue of the warning in force to the touchdown time in the database, both of which were recorded to the minute by different people.

The forecast that day

The Storm Prediction Center had this point in a General Thunderstorms Risk. The outlook in force was issued at 19:49 UTC.

SPC's Day 1 convective outlook as it stood when the tornado began, read at the touchdown point. The same archive is on the radar archive.

The air that afternoon

The radiosonde launches on either side of the tornado, from the nearest station that was launching then, drawn and analyzed the way Storm Lab does: the same diagram, the same parcel and shear definitions SPC's mesoanalysis uses.

Denver, CO (KDNR), 12:00Z

11.0 hours before the tornado, 175 km from the path. August 7, 2004.

Skew-T log-pSkew-T log-p diagram, Denver, CO at 12:00Z on 2004-08-07Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 43 joules per kilogram, CIN -245, lifted condensation level 2625 meters above ground. Wind barbs in knots down the right edge.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed. The warm shading is its CAPE, the cool shading the inhibition it has to break through.
HodographHodograph, Denver, CO at 12:00Z on 2004-08-07The wind through the lowest 10 kilometers as a curve, rings every 10 meters per second labeled in knots. Zero to 1 km storm-relative helicity -4 square meters per square second, 0 to 6 km bulk shear 18 knots.19395878Sfc1 km3 km6 km9 kmRMLM
The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km. RM and LM are the right and left moving storms Bunkers' method gives; the shaded area is the 0 to 1 km storm-relative helicity.
Mixed-layer CAPE
43 J/kg
Mixed-layer CIN
-245 J/kg
Surface CAPE
86 J/kg
Mixed-layer LCL
2625 m above ground
0-6 km bulk shear
18 kt
0-1 km bulk shear
10 kt
0-1 km storm-relative helicity
-4 m²/s²
0-3 km storm-relative helicity
4 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0
0-3 km lapse rate
5.5 K/km

Open this sounding in Storm Lab

Denver, CO (KDNR), 00:00Z

1.0 hours after it, 175 km from the path. August 8, 2004.

Skew-T log-pSkew-T log-p diagram, Denver, CO at 00:00Z on 2004-08-08Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 44 joules per kilogram, CIN -108, lifted condensation level 2882 meters above ground. Wind barbs in knots down the right edge.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed. The warm shading is its CAPE, the cool shading the inhibition it has to break through.
HodographHodograph, Denver, CO at 00:00Z on 2004-08-08The wind through the lowest 10 kilometers as a curve, rings every 10 meters per second labeled in knots. Zero to 1 km storm-relative helicity 76 square meters per square second, 0 to 6 km bulk shear 18 knots.1939Sfc1 km3 km6 km9 kmRMLM
The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km. RM and LM are the right and left moving storms Bunkers' method gives; the shaded area is the 0 to 1 km storm-relative helicity.
Mixed-layer CAPE
44 J/kg
Mixed-layer CIN
-108 J/kg
Surface CAPE
119 J/kg
Mixed-layer LCL
2882 m above ground
0-6 km bulk shear
18 kt
0-1 km bulk shear
13 kt
0-1 km storm-relative helicity
76 m²/s²
0-3 km storm-relative helicity
110 m²/s²
Significant tornado parameter
0.0
Supercell composite
-0.0
0-3 km lapse rate
8.7 K/km

Open this sounding in Storm Lab

The surface observations

La Junta Municipal (LHX), 38 km from the path, in the two hours either side.

Time (UTC)Temp (°F)Dew point (°F)WindGust (kt)Pressure (mb)Weather
21:53 UTC895990° 5 kt1014.9
00:53 UTC7057120° 13 kt1019.3

From the Iowa Environmental Mesonet's archive of airport observations.

The radar

The Pueblo radar (KPUX), 85 km away, was scanning. The volume nearest the touchdown began at 22:57 UTC.

Open the radar archive at this moment, over the track

Reflectivity and velocity, decoded from the Level II archive in the browser. Volumes take a few seconds to open the first time.

What was reported nearby

Local storm reports within 60 km of the path, in the three hours either side.

Time (UTC)ReportWhereCountyRemark
22:55 UTCTORNADO1 S ArlingtonKiowa, CO1ST TORNADO ON GROUND AT 455 PM AND REMAINDED ON GROUND UNTIL AT LEAST 515 PM. A SECOND TORNADO WAS REPORTED SIMULATANEOUSLY FROM 512 PM TO AT LEAST 515 PM. TORNADOES MOVES SLOWLY SOUTHEAST. NUMEROUS REPORTS FROM EM...CS
23:45 UTCTSTM WND DMGLas AnimasBent, COPOWER POLES DOWN IN TOWN. LARGE BRANCHES BROKEN OFF TREES. RAILROAD CROSSING GATES BROKEN OFF DUE TO WIND.
23:58 UTCTORNADO1 W HastyBent, COTORNADO TOUCHED DOWN 1 MILE WEST OF HASTY AND TRAVELED ABOUT 1 MILE N OF HASTY. GARAGE DESTROYED.
00:15 UTCTSTM WND GST 58LamarProwers, CO
00:20 UTCTSTM WND DMGWileyProwers, COPOWER POLES DOWN
00:32 UTCTSTM WND DMGLamarProwers, COTREES DOWN

From the Iowa Environmental Mesonet's archive of National Weather Service local storm reports.

This ground now

The live radar over the trackEvery 2004 tornado in ColoradoEvery tornado in Colorado since 1950Warnings in force in Colorado nowThe forecast where you are

The other tornadoes of August 7, 2004

3 more were confirmed in the United States that day.

DateTimeRatingWherePath (mi)Width (yd)DeathsInjuriesDamage
August 74:55 PM MDTF0Kiowa, CO1.075
August 75:58 PM MDTF0Bent, CO1.075$10,000
August 76:43 PM MDTF0Prowers, CO0.550

What this means

Ratings are the survey's, read off the damage rather than measured; the rating scale is above. Tornado counts rise through the record as reporting improved, so a year in the 1950s is not comparable with one today except for the strongest tornadoes, which were always noticed.

Sources

NOAA Storm Prediction Center tornado database, 1950-2025, the official record kept by NOAA's Storm Prediction Center.